Much of the stuff that breaks on VW's breaks independent of mileage. For example: a Dual Mass Flywheel should NOT break after 30000 (mostly highway) miles. (compare that to a single-mass flywheel; which will basically last forever, because it's a solid hunk of steel or aluminum; there are clutch breakdown scenarios that will DAMAGE a flywheel to the point where it has to be resurfaced like a brake rotor, but single mass flywheels never had these sorts of problems - VW added moving parts to a component that didn't need to have moving parts, for what many car enthusiasts would consider to be no damn good reason).
A lot of the vacuum tubes, electrical relays, harness cables, and etc, break from age, and in VW's case, we're talking about 2-3 years.
IMO: the worst "reliability problem" VW's have, in the US, is their dealer network. They refuse to stand by their warranties, and they refuse to stand by their product. They charge outrageous rates. They inflate the prices of their parts. They void the warranty if you do your own oil change, because of "oil grade" issues: but their own service department sells oil NOT of the required 505.01 grade; and then the clerk would tell me "that's what we use in the shop" (to do dealer-service oil changes). In some diesel models, if you're not using the correct oil grade (or even if you are), your cams will wear in as little as 30,000 miles. That's not a cheap repair. I've read countless stories online of people with TDI VW's where they may still have $10k left on their car loan, then something breaks like the injection pump ($2000), or in particular, the particulate filter, where it grenades, and sends contamination up into the fuel system (because they burnout the filter by periodically injecting fuel), and this contamination will cause ongoing problems with operation of the engine until the ENTIRE fuel system is replaced, at an average cost of about $7000. They don't cover this repair under their shitty warranty. Then there's issues with ice buildup in the intercooler, which sends chunks through the inlet blades of the turbocharger. If you're lucky, those don't find their way into the cylinders and snap valves. But that's usually what happens. I've heard this happening to BRAND NEW cars, and at least those poor folks get warranty coverage.
This emissions fakery just seals the deal.